1. Field of the Invention
The present invention relates to an on-spot hydrophilic enhanced slide and the preparation method thereof. More particularly, it relates to a hydrophobic copolymer prepared by blending, grafting or co-polymerization of a hydrophobic material and a compound bearing functional groups such as anhydride, imide, cyclic amide, and cyclic ester, and application of the hydrophobic copolymer onto an organic or inorganic matrix to form an on-spot hydrophilic enhanced slide.
2. Description of the Related Arts
In the current bio-chip and bio-microarray technology, most of the preparation methods involve the treatment of a matrix surface with silanization, followed by the crosslinking reaction with biomaterials. In the silanization treatment, the surface of the substrate is activated based on its material, and then treated by a hydrophilic silane such as APTES. Afterwards, the crosslinking reaction is performed via a crosslinker such as glutaldehyde to immobilize biomaterials on the substrate. The shortcomings of the method include substrate dependence, long reaction time, poor homogeneity, low reaction efficiency, and the resulting low activity for the immobilized biomaterials. Moreover, the prepared covalent bonding surface is hydrophilic, which facilitates the phenomenons of crossover and contamination among spots when the hydrophilic surface is used for a high-density microarray.
U.S. Pat. No. 5,837,860 and WO 98/39481 disclose the treatment of glass or silicon wafer with hydrophobic silane such as mercapto-silane, and the immobilization of nucleic acid probes thereon. The method involves treating a substrate surface so that mercapto-groups (HS-) with hydrophobicity are covalently bonded thereon. The hydrophobic property is suitable for the immobilization of nucleic acids/nucleotides in high density. The method, however, requires the modification of the biomaterials to bear mercapto-groups, thereby forming disulfide bonds between the modified biomaterials and matrix surface. Blanchar, A. P. et al. (Biosensors and Bioelectronics, 1996, 11(6/7): 687-690) discloses coating photoresists onto a substrate and then development using the micro-electromechanical mask to form on-spot hydrophilic spots, wherein the region outside of the spots is hydrophobic. The preparation of high-density nucleic acid probe microarrays and in situ synthesis is carried out on this treated surface.
In these prior arts, blending, grafting or co-polymerization of a hydrophobic material and a compound bearing functional groups such as anhydride, imide, cyclic amide, and cyclic ester to prepare a hydrophobic copolymer is not disclosed. Further, the application of the prepared hydrophobic copolymer onto an organic or inorganic substrate to form an on-spot hydrophilic enhanced slide is also not disclosed.
It is therefore a primary object of the present invention to provide a method for preparing an on-spot hydrophilic enhanced slide, comprising: (a) preparing a hydrophobic copolymer in a solvent to obtain a solution of hydrophobic copolymer; (b) coating said solution of hydrophobic copolymer onto a substrate (e.g. organic or inorganic substrate); and (c) removing said solvent.
Another aspect of the present invention provides an on-spot hydrophilic enhanced slide, comprising: (i) a substrate (e.g. organic or inorganic substrate); and (ii) a layer of hydrophobic functional groups formed by a hydrophobic copolymer, wherein said layer is coated onto said substrate.
Yet another aspect of the present invention provides an on-spot hydrophilic enhanced microarray, comprising: (i) a substrate (e.g. organic or inorganic substrate); (ii) a layer of hydrophobic functional groups formed by a hydrophobic copolymer, wherein said layer is coated onto said substrate; and (iii) a biologically active material, which is immobilized onto said layer of hydrophobic functional groups.